In the making of many wines and spirits it is usual to mature the wine or spirit in wooden barrels. Barrel aging is a centuries-old practice to improve the characteristics such as taste and mellowness of wine. Usually, for quality wines, the barrels are made of oak. It is felt that the infusion of oxygen through the oak into the wine or spirits is an important aging process. Present understanding suggests that the aging process softens the wine by polymerization of the phenols with the involvement of oxygen. Some flavor is introduced by the oak material but it has not been established that the presence of oxygen at the wine-oak interface enhances the quality of the oak-induced flavoring. The oak flavor, for less expensive wines, may be obtained by introducing oak slabs or chips into the wine, which may be contained in stainless steel tanks.
The prior art which may be considered relevant to the present invention involves the modifications of barrels or containers used for the maturation of wines and spirits. The objects of these modifications are directed to decreasing the cost of the container compared to conventional stave barrel or to reduce the use of high-quality oak which is available in limited supply. An example of prior art may be found in the following patents.
U.S. Pat. No. 2,108,661 teaches the use of a single hollow wooden plug with very limited area which provides an interface with the wine in a container. The plug is filled with compounds for treating the wine. It is not used for the purpose of providing an interface to the atmosphere.
U.S. Pat. No. 2,114,009 describes a bored wooden dowel that does not provide a surface for the slow oxidation of wine, but rather is inserted to provide the oak flavor.
U.S. Pat. No. 2,203,229 discloses a plurality of different configurations of a hollow wooden stick which is inserted into a wine bottle to provide communication between the wine and the atmosphere for aging.
U.S. Pat. No. 3,942,423 teaches the use of a single hollow oak rod in a glass container to provide communication between the wine and oxygen in the atmosphere. The surface area of the rod is adjusted to provide the same surface area to wine volume ratio as with a conventional barrel.
U.S. Pat. No. 5,537,913 describes a number of configurations and sealing options to form hollow cylinders which are introduced into a container.
U.S. Pat. No. 6,378,419 replaces the barrel with an aging vessel with an internal slab of oak with cored passages so that compressed air may be circulated through the air passages to provide the wine-atmosphere interface.
Thus, the prior art seeks to provide a porous oak or wood member which communicates between the wine and the atmosphere which has substantially the same interface area to liquid volume ratio as that provided by the standard oak barrels which have been used for centuries to age wine.
The present invention recognizes that conventional barrel-aging of wine or spirits occurs near the interface of wine or spirits (hereinafter “wine”) and the interior barrel surface as a result of the infusion of oxygen from the atmosphere and that this interface area is related to the aging process.